WASHINGTON, Aug. 19 (Xinhua) -- U.S. consumer prices rose for the sixth straight month in July but at a slower pace.

Consumer Price Index (CPI), a main gauge of inflation, went up 0.1 percent in July on a seasonally adjusted basis, following a 0.3 percent increase in June, said the Labor Department on Wednesday. On a year-on-year basis, the index rose 0.2 percent.

The indexes for food and energy all rose slightly in July, said the department. The energy index rose 0.1 percent, as an increase in the gasoline index more than offset declines in other energy component indexes; the food index rose 0.2 percent as indexes for all six major grocery store food increased.

Excluding the volatile food and energy categories, the so-called core CPI rose 0.1 percent in July on a seasonally adjusted basis, compared to an increase of 0.2 percent in June. The core CPI was up 1.8 percent from a year earlier, the same as in June.

The U.S. Federal Reserve is looking for inflation to firm gradually as it considers when to raise benchmark interest rates. Fed officials expected that as the effects of transitory factors, such as low oil prices and strong dollars, dissipate and as the labor market improves further, inflation will move gradually back toward the central bank's 2 percent objective.

The Fed's preferred inflation gauge, the price index for personal consumption expenditures, has been below the central bank's 2 percent objective for years.